Crossbite is a form of misalignment of the teeth or 'malocclusion' which is where the upper teeth close inside the lower teeth. With a normal bite alignment, the upper teeth rest slightly outside the lower teeth.

Type of crossbite

Crossbites may involve the front teeth, the back teeth or all teeth. Crossbites may occur on one side or both sides.

  • 'Posterior crossbite' where the top set of teeth at the back come to rest inside the bottom teeth (often associated with a discrepancy in size of the upper and lower jaws).
  • 'Anterior crossbite' where the front teeth are affected, with the upper teeth coming to rest inside the lower set of teeth.
  • 'Single tooth crossbite' where only one tooth (normally to the front) is involved.

Up to one in six children have posterior crossbite with their baby teeth, with anterior crossbite affecting around one in twenty.


Crossbite may develop due to a number of factors. These include…

  • Genetic predisposition causing unusual development of the jaws and / or the teeth.
  • Teeth 'crowding' (where there is not enough room for permanent teeth as they erupt).
  • Excessive thumb sucking or dummy / pacifier use (which can in turn cause misalignment of teeth and/or palate deformation).

If not treated, crossbite can cause longer term issues such as…

  • Tooth decay.
  • Gum disease.
  • Uneven wearing of the teeth.
  • Jaw joint issues (which can in turn lead to problems with chewing, swallowing and breathing and cause headaches and pain).


Generally, crossbites – especially anterior crossbites, should be corrected as soon as they are noticed.

Crossbites can be treated with a variety of appliances depending on the particular problem. The most appropriate treatment will be discussed with you and will depend on the type of crossbite and how severe the problem is.

Related Information

Orthodontics for Children and Teens
Early Treatment